IL-4 is a substance produced by T lymphocytes which are human or animal immune response cells, and are known to act on B lymphocytes and to enhance production of an antibody such as IgE [Rinsho Meneki (Clinical Immunology), 27, 45-57 (1995)]. For many years IgE is known to take a significant part in the onset of an atopic disease. Further, IL-4 is known to act as an accelerator of inflammatory cell infiltration at lesions in allergic diseases [Cell, 62, 457-467 (1990)]. From these, it is considered that IL-4 is largely implicated in the onset of an allergic disease. Inhibition of IL-4 production, if successfully achieved, is therefore believed to make it possible to treat and prevent allergic diseases more fundamentally from their cause than conventional treatment and preventive methods making use of histamine release inhibitors, IgE or histamine effect inhibitors or the like.
As substances for inhibiting the production of IL-4, a group of sulfonium derivatives including suplatast tosilate is well-known [Japan. J. Pharmacol., 62, 27-30 (1993)]. They are formulated into oral drugs and are used to treat allergic diseases such as atopic dermatitis, itching and pruritus, and the like, but their effects are not sufficient. In addition, their administration routes are limited because they have low percutaneous or transdermal absorption due to their structures. There is hence an outstanding need for IL-4 production inhibitors, antiallergic agents, and atopic dermatitis preventives and improvers, which are excellent in percutaneous or transdermal absorption, stability and safety.
In the case of one having overdrying skin or oversensitive skin and one suffering from atopic dermatitis, on the other hand, the skin is especially sensitive so that the skin tends to develop itching, pruritus, eczema or the like even by mild stimulation. Further, an allergic reaction to a house dust mite antigen, food or the like, psychological stress or the like acts as a deteriorating factor, thereby tending to result in a skin trouble. Use of medicinal bath preparations (JP 2-115117 A), which were added with conventional oil ingredients or humectants, were not able to sufficiently bring about fundamental preventing and improving effects although moistened skin feeling was available temporarily. There is accordingly an outstanding desire for bath medicine compositions, which have high effectiveness for improving skin roughness or dryness and for preventing and improving atopic dermatitis even for those having overdrying or oversensitive skin.